Circuit-breaker indicating device



C. F. KETTERING.

CIRCUIT BREAKER I NDICATING DEVICE.

APPLICATION FILED Aue.2 0. 1914.

1 ,336, 1 12, Patented Apr. 6, 1920.

Mai

CHARLES F. KETTERING, F DAYTON, 01-110, ASSIGNOR 1'0 THE DAYTON ENGINEERING: I LABORATORIES COMPANY, A. CORPORATION OF UHIO.

CERCUIT-BREAKEE ENDIICATING DEVICE.

Specification of Letters Patent.

Patented Apr. 61, M926 new and useful Improvements in Circuit- Brcaker Indicating Devices, of which the I following is a full, clear, and exact description.

The subject of this application is an improvement in apparatus for use with an electric circuit and designed to indicate the existence therein of an abnormai How of current. ihe invention is applicable to electric circuits of wide variety, but it was especially designed for use in motor vehicles in connection with the circuits therein, including a dynamo, a secondary battery, and ignition device, lamps and other elements, and the illustration herein given will be confined to such uses.

It is well known that in circuits or this nature, it is customary to insert one or more fuses, which, under conditions of a'bnormai currentfiow are blown out, thus interrupting the circuit and protecting the working devices therein from injury Or destruction. The main object of the present invention, however, is to provide a means which will prevent the burning out of the working devices, and at the same time attord an unmistakable indication of the existence of abnormal conditions, to enable an attendant to take. immediate steps to correct them.

To this end the invention consists in an improved form of circuit interrupter which, when aitected by an abnormal current, will operate to intermittently break the circuit as long as the conditions exist which en danger the devices therein, and likewise give the operator some clear indication of this condition.

lit is therefore among the objects ot the present invention to provide an overload indicating device in the form of a circuitbreaker which will make and break the circuit successively and thus give warning of the overload condition by means of successive flickering of the lights or an audible clicking of the interrupter mechanism; turthermore, for the best results, the successive breaks and makes should be retarded or spaced apart sufficiently to give a more pronounced etfect of the fli kering, or to the audible clicking; and" in addition, to reduce the current output as much as possible during the operation of the interrupter, so that although visible or audible indication is given to "denote trouble on the line, yetthis indication will beat the expense of small current output.

Further objects and advantages or the invention will be understood from the description which follows, and by reference to the accompanying drawings, in which the device is shown in its preferred form.

Figure is a diagram of the. circuit connections, showing also the relations and illustrating the functions of the several parts of the apparatus.

Fig. 2 is a view in side elevation of the device embodying the invention.

Fig. 3 is a top plan view of the apgaratus shown in Fig. 2.

Fig. i is a cross-sectional view taken on 7 the line li of Fig. 2.

As above stated, the illustration is of an electric system for motor vehicles in which 29 is the dynamo, 21 the secondary battery in circuit therewith through wires 23, 2t and or otherwise, in any suitable manner, 33 the lighting circuit and 37 the primary coil of the ignition device, in parallel with the lighting circuit by wires and -10, the latter torming a circuit which includes also 8 the timer or circuit interrupter 39. The main or work circuit in the present instance is connected at the point 28, with both the generator and the battery circuits. T he circuit comprises the wire 30, which leads to the current interrupter or indicating device 81, to be hereinafter described in detail.

The wire 32 tends to complete one side of the lighting circuit and connects to one side of the lamps, while the other side of the said circuit and the main circuit are completed by means of the wire 34. The ignition circuit by the wires above mentioned is between the points 36 and 41 of the main circuit.

The device for interrupting and protecting the circuits of the present case is stru'c- .turally illustrated in Fig. 2, and is shown as vices may be combined with each of the work circuits, in which event each will be equipped with some means to give a diiferent indication, or signal, when abnormal conditions occur in the respective circuits, in order to show the specific circuit wherein these conditions exist.

A detailed description of the interrupter will now be given. The wire 30, which is connected directly to the wire 24, and also to the wire 23, leading respectively from the battery and generator, 'is connected with the heavy series coil 45 of the indicating device or interrupter 31. This coil 45 is wound about a core 46, and is also connected with the fine wire coil 47, by means of the branch connection 48. The windings 45 and 47 and the core 46, constitute an electromagnet, which is adapted to control the operation of the armature 49.

The heavy winding 45 is electrically connected with the plate 50 in any suitable man ner, which in turn is so mounted that it is in contact with the plate 51. This plate 51 is provided with a supplemental contact plate 52, which is normally in contact with the plate 54; this plate 54 connecting with the wire 32 of the main circuit.

It has been explained that the fine winding 47, which may be termed the retarding coil, has electrical connection with the coil 45, by means of the branch wire 48.- The opposite end of this coil 47 is electrically connected with the auxiliary contact plate 55, which in turn is actuated by the operation of the armature 49 and the consequent engagement of this auxiliary spring contact plate by the plate 51. The arrangement of the auxiliary plate 55 and the contact plate 51 is such that a slight wiping contact will occur when the armature 49 is operated to move the above mentioned plates 51 and 55, respectively.

A small shunt 56, the resistance of which increases with its temperature, such as iron wire, is connected with the wire 30 and the contact plate 50, in any suitable manner, and is adapted to practically short circuit the heavy winding 45, except under certain conditions which will be fully explained hereinafter.

The shunt element 56 and the winding 45 are so proportioned inresistance that substantially the required amount of current to properly operate the lighting, ignition and accessory circuits, can be passed by them,

. without affecting other elements of the interrupter.

If, for any reason, a short circuit should inadvertently occur in the lighting, ignition or accessory circuits, an abnormal current would flow through both the shunt element 56 and the winding 45. The shunt element having this increased current flowing therethrough, will quickly heat up and thereby This - would cause a still greater proportion of the current to flow through the windings 45, the circuit-being completed to the work circuit, via contact plate 50, and plates 51, 52 and 54 to the main wire 32.

A spring 58 is so constructed that the tension will hold the armature 49 in unattracted position, as long as the flow of current through the shunt element 56 and winding 45 remains normal. As soon as an increased current (to a predetermined amount according 'to the design) is caused to flow through the windings 45, as has been heretofore described, the tension of the spring 58 will be overcome, and the armature 49 will be attracted, causing the contact between plates 50 and 51, 52 and 54, to be broken.

By referring to Figs. 2 and 3, it can be seen that the auxiliary contact plate 55 is riveted to the contact plate 51 in such manner that no movement will be transmitted to said contact plate 55, until the contact plate 51 moves far enough to force the plate 55 out of contact with the plate 54. This results in the contact between 55 and 54 being broken at a time slightly subsequent to the above described breaking of the contact at the points 50, 51, 52 and 54; and a consequent making of the contact at the points 54 and 55, just prior to the making at the other points, when the armature 49 again moves downward toward its normal position.

When the different elements of the interrupter are in their normal positions, as shown in Figs. 1 and 2, the auxiliary contact 55, being made of any suitable resilient conducting metal, is slightly under tension. Thus, when the contact plate 52 is freed out of engagement with the plate 54, it carries said plate 55 to disconnect from plate 54,

with a sliding movement, preventing oxidizing or pitting at the point of contact.

In Fig. 3 the shape of the unitary double contact plates 51 and 52 is such that both of said contacts together form the letter U, and said contacts are being fastened to and in sulated from the armature 49 in any suitable manner. The armature is pivoted to the frame 59 at 60.

The U-shaped double contact plate 51 and 52- as shown in Fig. 3, has the base portion of the U located at the left in Fig. 3, and 1 fastenedito the armature 49 so that in the manner in which Fig. 3 is illustrated, the

U is lying on one side with the base at the left and with one of the arms 51 extending to the right over the contact late 50, while the other arm extends similar y to the right over the contact plate 54, but as shown, this arm is almost all concealed by the overlying contact plate 55.

In Figs. 3 and 4, the stationary contact plates 50 and 54, coijperating respectively J with the 'movable double contact plates 51 and 52, are shown as being held in position by the insulated screws 63 and 64. The

terminal plates, having suitable terminal leads 65 and 66 are also shown in Fig. 3.

The shunt element 56 is shown held in position by the screws '63 and 64, one end contacting with the stationary contact plate 50, the other with. the terminal and drop lead 66 and 66 respectively. The leads 61 and 62 in Fig. 4 are the two extremities of the heavy winding 45, one being connected to the stationary contact plate 50, the other to the drop lead 66.

As has already been described, when an abnormal or overload current flows through the main circuit, the result is to heat up the iron wire 56 and thereby'throw enough cur-.

- rent through the shunted winding 45 of the circuit breaker, as to operate the armature 49 and break the main line "circuit at the points 50, 51, 52 and 54.

But it will be observed that the auxiliary winding 47 of the circuit-breaker is still in the mam circuit, that is, the current can still flow through the winding 47, wire 57, plates and 54, out to the main line 32.

point 54.-55. Likewise, less resultant 'current is used if the armature 49 is retarded in its re-making movement.

Thus, the circuit breaker may be said to comprise-a main make and break point, and an auxiliary make and break point, and these are operated successively by the arma ture, so that the breaking at the main point still leaves the auxiliary point operative under the control of its auxiliary interrupter coil, (the coil 47), which exercises a retarding efi'ect when both make and break points are successively and intermittently operated, and at the same time there is a reduction in the resultant current utilized by the circuit breaking operation, as above explained.

But this coil 47 is thereby still acting to attract the armature 49 and thus break the circuit at the second set of .contact points, namely, the points 54 and 55, and when this occurs, the main line circuit is completely broken. Whereupon, the core 46 will become demagnetized and the armature 49 will then, under its spring tension, tend to move back toward normal osition.

By using the additional or retarding coil 47, a sluggish or retarding efi'ect is exercised upon the operation of the armature 49. Thus, after the main circuit has been completely broken at both sets of make and break points, the movement of the armature 49 toward the right in Fig. 1, will first partly reestablish the main circuit at the make and break point 54-55. This establishes the circuit through the high resistance coil 47 which in turn exercises a pulling effect upon the armature, to retard its further movement to the right; s'o that although the armature may contlnue ltS movement to the right and thus make the circuit at the other make and breakpoint than would be the case if it vibrated solely under the influence of the coil 45 and a single makeand break point.

H therefore,-there is enough resultant current to illuminate the electric lamps on the Work circuit, these lamps will indicate the presence of the trouble by flickering, and at least the interrupter armature will give audible indication by the successive clicking sound. Furthermore, the flickering or the audible clicking will be spaced apart to give a more appreciable signal, by reason of the retarding effect spoken of.

It will of course be understood from the construction described. that it is the vibratory movement of the armature which causes the audible clicking or tapping referred to, as for example the striking of the armature against the core.

From the above description, it will be seen, that the interrupteris effective, not only as to the lighting circuit, but also as to the ignition circuit. circumstances, it may be desirable to have the interrupter efi'ective only with respect to the lighting circuits. When this is the While the form of mechanism herein shown and described constitutes a preferred fornrof embodiment of the present invention, it is to be understood that other forms might be adopted, all coming within the scope of the claiins which follow. 7

What I claim is 1. In a circuit-breaker indicating device,

. having main contacts and auxiliary contacts in shunt therewith; means for opening the main contacts upon excessive current-flow;

and means brought into action by the opera- 1 tion of said first means for extending the opening movement of said main contacts and then opening the auxiliary contacts.

2. In a circuit-breaker indicating device, a series coil; an armature in operative relation thereto; main series contacts operated by said armature; a circuit in shunt with said main contacts, said circuit containing auxiliary contacts operated by said armature; and an auxiliary coil operatively related to the latter. i

magnet to 3. In a circuit-breaker indicating device having main contacts and auxiliary contacts in shunt therewith; means for opening the main contacts upon excessive current flow;

means brought into action by the opera-' tion of said first means for extending the opening movement of said main contacts and then opening, the auxiliary contacts; and means for returning the circuit breaker to normal position after each actuation upon excessive current flow.

In a circuit breaker indicating device, the combination with the main work circuit, of main'and auxiliary make-and-break con tacts insaid circuit; an electro-magnet operated by the main circuit current; means conn cted with said main and auxiliary contacts operated intermittently by said break the main circuit byquick breaks of i rst the main contact and then re auxiliary contact and then make inzuncircuit; and a thermal-resistance shunted around said magnet, operupon an abnormal flow of current in successive I the main circuit to -send increased current through the coils of the magnet whereby to operate the latter,

5. In a circuit-breaker indicating device, the combination with a main circuit and a circuit-breaker means for intermittently breaking said circuit upon an abnormal flow or current therethrough; of an electrical de vice normally 'shcrt-circuiting the circuit breaker but operated by an abnormal flow of current to send current through the circuit breaker to operate the latter,

6. ln a circuit-breaker indicating device, the combination with a main circuit and circuit-breaker means for intermittently breaking said circuit upon an abnormal how of current therethrough; said circuit breaker means including an electro-magnet and armature with auxiliary provisions for operating upon said armature to delay its normal time of remaking of said main circuit.

7, In a circuit breaker indicating device, the combination with a main circuit, of a circuit breaker coil wound upon a core; armature operated by the magnetic effect of said core to intermittently break the main circuit when an abnormal flow of current passes through said circuit breaker coil; and means for setting up an auxiliary magnetic efi'ect in the core after the main circuit connection is broken by said armature, whereby the movement of this armatureto its normake a-nd-break mal position to completely close the main circuit connectionwill be retarded;

8. In a circuit-breaker indicating device, the combination with a main circuit; of circuit-breaking means in said circuit comprising a core; an armature mounted in vibrating relation to said core and adapted to produce a signal upon striking said core; a spring tending to move said armature away from said core; and electromagnetic devices adapted on passage of abnormal flow of current first to attract said vibrating armature to open the main circuit and thereafter to resist the action of said spring in returning said armature whereby to retard the closing of the main circuit.

9. In a circuit-breaker indicating device, the combination with a main circuit; of cir- Quit-breaking means in said circuit comprising a core; an armature mounted in vibrating relation to said core and adapted to produce 'a signal upon striking said core; a spring tending to move said armature away from said core; electro-magnetic means adapted to attract said armature to open said main circuit; and auxiliary electromagnetic means rendered operative by said first named electromagnetic means for resisting the return of said armature and conscquently retarding the closing of said main circuit.

10. In a circuit breaker indicating device, the combination with a main work circuit of a first parallel circuit comprising a thermal resistance as one branch and a main magnet winding as the other branch; a second parallel circuit comprising main make-andbreak contacts in one branch and a second branch including an auxiliary magnet winding and auxiliary make-and-break contacts, said parallel circuits being in series in said main Work circuit; a magnet core cotiperating with said magnet windings; an armature coiiperating with said core; a spring tending to maintain said armature in unattraclcd position; and means cooperating with said contacts and armature whereby to separate first the main contacts and then the auxiliary contacts as the armature is moved toward the magnet core.

In testimony whereof I affix my signature in the presence of two subscribing witnesses.

' CHARLES F. KETTERING. Witnesses:

J. W. MCDONALD, O. D. MoWRY. 

